U.S. patent number 5,738,434 [Application Number 08/603,421] was granted by the patent office on 1998-04-14 for flash light.
This patent grant is currently assigned to Regitar Power Co., Ltd.. Invention is credited to Pel Chang Sun.
United States Patent |
5,738,434 |
Sun |
April 14, 1998 |
Flash light
Abstract
A flash light is provided in which the rotary positioning
mechanism that retains the lamp head holder to the hollow
cylindrical handle at any of a variety of angular positions
includes a curved stub tube extending from the sloping bottom wall
of the lamp head holder. The stub tube has an internally threaded,
straight top end and a straight bottom end. The bottom end extends
from the top end at an angle and perpendicularly intersects the
sloping bottom wall of the lamp head holder. A plurality of
circular recesses are formed in the sloping top wall of the hollow
cylindrical handle and radially spaced around the center of the
sloping top wall. A spring is mounted within the top end of the
curved stub tube. A first steel ball is mounted in the bottom end
of the curved stub tube, and a second steel ball is mounted within
the top end of the curved stub tube and disposed between the first
steel ball and the spring. A hold down screw is threaded into the
top end of the curved stub tube to hold the spring therein and to
force the first steel ball into engagement with one of the circular
recesses.
Inventors: |
Sun; Pel Chang (Taichung,
TW) |
Assignee: |
Regitar Power Co., Ltd.
(Taichung, TW)
|
Family
ID: |
24415367 |
Appl.
No.: |
08/603,421 |
Filed: |
February 20, 1996 |
Current U.S.
Class: |
362/199; 362/205;
362/287; 362/418 |
Current CPC
Class: |
F21L
15/06 (20130101); F21L 2/00 (20130101) |
Current International
Class: |
F21L 007/00 () |
Field of
Search: |
;362/197,199,205,202,285,287,418,419,421,427,208 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Sember; Thomas M.
Attorney, Agent or Firm: Lei; Alfred
Claims
I claim:
1. A flash light comprising a hollow cylindrical handle, a rotary
positioning mechanism, a lamp head holder rotatably mounted on said
handle and retained in any of a series of angular positions by said
rotary positioning mechanism, a lamp bulb holder being mounted
within said lamp head holder, a lamp head secured on said lamp head
holder to hold a lamp bulb on said lamp bulb holder, two conductors
connected to said lamp bulb, said lamp head holder having a sloping
bottom wall, said hollow cylindrical handle having a sloping top
wall disposed in contact with said sloping bottom wall of said lamp
head holder, said rotary positioning mechanism including a curved
stub tube extending upwardly from said sloping bottom wall of said
lamp head holder, said curved stub tube having an internally
threaded, straight top end and a straight bottom end extending from
said top end at an angle and perpendicularly intersecting said
sloping bottom wall of said lamp head holder, a plurality of
circular recesses formed in said sloping top wall of said hollow
cylindrical handle and radially spaced around a central portion of
said sloping top wall, a spring mounted within said top end of said
curved stub tube, a first steel ball mounted in said bottom end of
said curved stub tube, a second steel ball mounted within the
curved stub tube and disposed between said first steel ball and
said spring, and a hold down screw threaded into said top end of
said curved stub tube to hold said spring within said curved stub
tube and to force said first steel ball into engagement with one of
said plurality of circular recesses.
2. The flash light as claimed in claim 1 wherein said lamp bulb
holder comprises an insulative stepped upright tube, a first metal
spring mounted on an outside surface of said stepped upright tube,
and a second metal spring mounted in an interior portion of said
stepped upright tube, said first and second metal springs being
respectively connected to said two conductors, said first metal
spring and said second metal spring being disposed in contact with
a respective ring contact and tip contact of said lamp bulb.
Description
BACKGROUND OF THE INVENTION
1. Field of the invention
This invention relates to flash lights. More particularly, this
invention relates to a flash light which is durable, and can be
accurately and positively adjusted to position the lamp head at any
one of a series of angular positions.
2. Prior Art
In conventional flash lights, metal springs are commonly used in
the lamp head holder to contact the ring contact and tip contact of
the lamp bulb. However, because the metal springs tend to wear with
use, bad electrical contact results. Furthermore, conventional
flash lights commonly use a rotary positioning mechanism to
adjustably retain the lamp head holder to the hollow cylindrical
handle at any of a variety of angular positions. That rotary
positioning mechanism, as shown in FIG. 1, comprises a tube raised
from the sloping bottom wall of the lamp head holder at an angle, a
spring mounted within the tube, and a steel ball forced by the
spring into engagement with one of a set of circular recesses
disposed in the sloping top wall of the hollow cylindrical handle.
However, because the bottom end of the tube is not raised
perpendicularly from the sloping bottom wall of the lamp head
holder, the horizontal center line of the steel ball does not
coincide with the top surface of the sloping top wall of the hollow
cylindrical handle when the steel ball is forced into engagement
with a circular recess. When the lamp head holder is turned
relative to the hollow cylindrical handle to shift the steel ball
from one circular recess to another, a rotary torque is produced
against the periphery of the respective circular recess. Therefore,
these circular recesses tend to wear with use.
SUMMARY OF THE INVENTION
This invention is directed to an improved flash light.
According to one aspect of the present invention, the rotary
positioning mechanism includes a curved stub tube extending from
the sloping bottom wall of the lamp head holder and which has an
internally threaded, straight top end. The curved stub tube has a
straight bottom end extending from the top end at an angle and
perpendicularly intersecting the sloping bottom wall of the lamp
head holder. A plurality of circular recesses are formed in the
sloping top wall of the hollow cylindrical handle and spaced around
the center of the sloping top wall. A spring is mounted within the
top end of the curved stub tube. A first steel ball is mounted in
the bottom end of the curved stub tube, and a second steel ball is
mounted within the top end of the curved stub tube and disposed
between the first steel ball and the spring. A hold down screw is
threaded into the top end of the curved stub tube to hold down the
spring and to force the first steel ball into engagement with one
of the circular recesses. According to another aspect of the
present invention, the lamp head holder comprises an insulative
stepped upright tube, a first metal spring mounted on the outside
of the stepped upright tube and a second metal spring mounted on
the inside of the stepped upright tube. The first and second metal
springs are respectively connected to the two opposite ends of the
battery by two conductors through a switch, wherein the first metal
spring and the second metal spring support the lamp bulb and make
contact with the ring contact and tip contact of the lamp bulb
respectively.
Other objects of the invention will in-part be obvious, and in-part
hereinafter be pointed out.
The invention accordingly consists of features of structures and a
method, combinations of elements, arrangement of parts and steps of
the method which will be exemplified in the constructions and
method hereinafter disclosed, the scope of the application of which
will be indicated in the claims that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic drawing showing the rotary positioning
mechanism of a prior art flash light;
FIG. 2 is an exploded view of a flash light according to the
present invention;
FIG. 2A is an exploded view of the rotary positioning mechanism of
the flash light shown in FIG. 2;
FIG. 3A is a sectional view in an enlarged scale of the lamp bulb
holder of the flash light shown in FIG. 2, showing the metal
springs mounted in the stepped upright tube and connected to the
respective conductors;
FIG. 3B is similar to FIG. 3A but showing the lamp bulb
installed;
FIG. 4A is a sectional view in an enlarged scale of the rotary
positioning mechanism of the flash light shown in FIG. 2, showing
the lower steel ball forced into engagement with one circular
recess; and
FIG. 4B is similar to FIG. 4A but showing the lower steel ball
moved out of the circular recesses.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
For the purpose of promoting an understanding of the principles of
the present invention, reference will now be made to the embodiment
illustrated in the drawings. Specific language will be used to
describe the illustrated embodiment. It will, nevertheless, be
understood that no limitation of the scope of the invention is
thereby intended, and that it is contemplated that such alterations
and further modification of the illustrated device, and such
further applications of the principles of the invention illustrated
herein, as would be recognized by one skilled in the art to which
the invention relates are incorporated herein.
Referring to FIG. 2, a flash light in accordance with the present
invention is generally comprised of a lamp head 10, a lamp bulb
holder 21, a lamp head holder 20, and a hollow cylindrical handle
40. The lamp head 10 is fastened to the lamp head holder 20 by a
screw joint to hold the lamp bulb holder 21 at the sloping bottom
wall 27 of the lamp head holder 20 and a lamp bulb 11 on the lamp
bulb holder 21. The lamp bulb holder 21 has an insulative, stepped,
upright tube 24. A first metal spring 22 is mounted around the
upright tube 24 to support the lamp bulb 11 and to contact the ring
contact of the lamp bulb 11. A second metal spring 25 is mounted
within the upright tube 24. Two conductors 23 are connected between
the metal springs 22, 25 and the two opposing ends of a battery
(not shown) disposed in the hollow cylindrical handle 40 through a
rotary switch (not shown). The lamp head holder 20 is rotatably
coupled to the hollow cylindrical handle 40 and retained at any one
of a plurality of angular positions by a rotary positioning
mechanism 30.
Referring additionally to FIG. 2A, the aforesaid rotary positioning
mechanism 30 is shown to include a curved stub tube 26 extending
from the sloping bottom wall 27 of the lamp head holder 20. Stub
tube 26 has an internally threaded, straight top end 262 disposed
in vertical alignment with the longitudinal central axis of the
hollow cylindrical handle 40. Stub tube 26 has a straight bottom
end 261 extending from the top end 262 at an angle and
perpendicularly intersecting the sloping bottom wall 27 of the lamp
head holder 20. A plurality of circular recesses 41 are formed in
the sloping top of the hollow cylindrical handle 40 and radially
spaced around the center of the sloping top. A spring 31 is mounted
within the curved stub tube 26, and two steel balls 32, 33 are
mounted within the curved stub tube 26 and forced into engagement
with a selected one of the circular recesses 41 by the spring 31. A
hold down screw 34 is threaded into the threaded top end 262 of the
curved stub tube 26 to hold the spring 31 within stub tube 26. When
the lamp head holder 20 is turned relative to the hollow
cylindrical handle 40, the bottom steel ball 33 is shifted between
the circular recesses 41, the angular position of the lamp head
holder 20 thereby being adjusted.
Referring to FIG. 3A, the first metal spring 22 is mounted around
the exterior of upright tube 24. The second metal spring 25 is
mounted within the upright tube 24, and the two conductors 23 are
respectively inserted through respective holes in the lamp head
holder 21 and connected to the metal springs 22, 25. The opposite
ends of the conductors 23 are respectively connected to the two
opposite ends of the battery.
Referring to FIG. 3B, the lamp bulb 11 is supported on the first
metal spring 22 and the second metal spring 25. The lamp bulb's
ring contact and tip contact are respectively connected to the
conductors 23 through the first metal spring 22 and the second
metal spring 25. When the switch is switched on, the circuit is
closed, and battery power is transmitted to the lamp bulb 11,
causing the lamp bulb 11 to give off light. Conversely, when the
switch is switched off, battery power is cut off from the lamp bulb
11, and thereby turning off the lamp bulb 11. The metal springs 22,
25 are provided to ensure accurate contact between the conductors
23 and the lamp bulb 11. Because the first metal spring 22 is
supported on the outside of the upright tube 24 and the second
metal spring 25 is supported on the inside of the upright tube 24,
the metal springs 22, 25 are not displaced and will not wear
quickly with use.
Referring to FIGS. 4A and 4B, the spring 31 and steel balls 32, 33
are mounted within the curved stub tube 26, wherein the lower steel
ball 33 is retained in the bottom end 261 of the curved stub tube
26 and moved with the lamp head holder 20 between the circular
recesses 41 of the hollow cylindrical handle 40. The upper steel
ball 32 and the spring 31 are retained in the straight top end 262.
The bottom end 261 of the curved stub tube 26 perpendicularly
intersects the sloping bottom wall 27 of the lamp head holder 20
(see FIGS. 2 and 2A). By that arrangement the horizontal center
line of the steel ball 33 coincides with the bottom surface of the
sloping bottom wall 27 of the lamp head holder 20. Therefore, when
the lamp head holder 20 is turned relative to the hollow
cylindrical handle 40 to move the steel ball 33 between the
circular recesses 41, no lateral component of force is produced.
Furthermore, because there is not any difference of elevation
between the steel ball 33 and the sloping top of the hollow
cylindrical handle 40, no torque is produced during the rotary
motion of the lamp head holder 20 relative to the hollow
cylindrical handle 40. Therefore, the lamp head holder 20 can be
smoothly adjusted to the desired angular position.
The present invention is naturally not limited in any sense to the
particular features specified in the foregoing description or to
the details of the particular embodiment which has been chosen in
order to illustrate the present invention. Consideration can be
given to all kinds of variations of the particular embodiment which
has been described by way of example, and of its constituent
elements, without thereby departing from the scope of the
invention. This invention accordingly includes all of the means
constituting technical equivalents of the means described.
* * * * *